Stamp and method of forming the same



@cfi. 9 1923.

G. A. GARDHAM STAMP AND METHOD OF FORMING THE SAME Filed May 12, 1920 2 Sheets-Sheet 1 Qttmumgo G. A. GAIRDHAM STAMP AND METHOD OF FORMING THE SAME Filed May 12, 1920 2 sheeks sheet 2 m m M PM a? Y Q a w my K G Patented (lot. 2

ARTHUR GARDHAM, 01E HIGHLAND PARK, EHCHIGA'N, JA$SIGNUE HALF 'ICG ARVIN C. WEBSTER, F

or can IBEQDRQXT, TEIUHIGAN.

STARE? AND METHOD OF FORT-KING: THE

Application filed may 12, 1220. fierial No. 3803141.

To all whom it may concern:

lie it known that l, Gnonon A. GARDHAM, a citizen of the United @tates of America, residing at Highland Park, in the county of ll ayne, and r'tate of Michigan, have inrented certain new and useful improvements in i temps and Methods of Forming the Same, of which the following is a specification, reference being bad therein to the acompanying drawings.

The invention relates to stamps and the method of forming the same, and is particularly applicable to the engraving and embossing art in which the stamps or dies may be formed with raised patterns, letters, figures, etc. 'lhe invention has for one of objects the provision of a stamp which great strength and is durable. Another object resides in the method of rapidly torming the stamps and moreover by mechanical means instead of by manual operations Further objects of the invention reside in; advantageous features more fully herein after set forth.

In the drawings:

Figure l is a front elevation of a machine for forming the stamp;

igure 2 is a top plan view thereof, with the upper part of the machine omitted;

Figure 3 is a perspective view of a completed stamp.

1 is a vise comprising the interchangeable steel jaws 2 for holding the tool steel blank 3 during the heating and forming opera tions. This blank preferably has its outer face 4 located a substantial distance beyond the outer faces 5 of the jaws and furthermore, has the outwardly tapering and portion 6 leading from the main body portion 7 thereof to the outer face a.

8 is an air hammer slidably mounted in the slide 9 upon the machine and 10 is a suitable matrix removably mounted in the air hammer. The arrangement is such that the matrix is positioned so that upon the sliding movement of the alr hammer toward the vise 1, the matrix will engage the outer face 4 of the blank 3. 11 is a suitable foot lever for controlling the movement of the air hammer 8.

ln operation the blank 3 is clamped between the jaws 2 of the vise 1 with its outer face 4 adapted to be engaged by the matrix 10. pon actuating the foot lever 11, the air hammer 8 will be moved toward the jaws 2. and the matrix Ml-mounted hammer will strike' a succession of blows upon the outer face l of the blank. Due to the fact that there is this succession of blows by the characters, such as letters, figures. etc, formed upon the blank are clearly defined and require substantially no hand work to place the formed blank in condition to be used as a stamp.

For the purpose of forming a better and more durable stamp, the blank is heated before being operated upon by the matrix. in detail 12 are heating terminals upon opposite sides of the blank 3 and adapted to engage the opposite sides of portion 7 of the blank. ininal control levers to which the heating terminals 12 are secured. These control levers are pivotally mounted at 1 1 upon the machine and are adapted to be swung inward toward each other to bring the heating terminals into firm engagement with the blank 3. 15 is a transformer comprising the primary circuit 16 and the secondary circuit 1'? which secondary circuit is electrically connected to the heating terminals 12. 18 is a housing for a control lever switch to the circuit breaker preferably mounted upon one of the heating terminal control levers 13. 19 is a suitable housing containing a switch and fuses for connecting the power feed line 20 to the primary circuit 16 of the transformer through the circuit breaker control switch in the housing 18. This switch is suitably actuated from the rock arm 21 pivoted upon the same control lever as the housing 18 is mounted upon and having arm extending adjacent to the handle portion 22 of the control lever whereby the operator may move the control leverstoward each other to bring the heating terminals 12 into engagement with the blank 8 and then readily connect the transformer to the power feed line through the circuit breaker control switch.

After the blank has been heated to the desired temperature, the transformer is dis connected from the power feed line by actuating the circuit breaker switch, and the. control lovers are moved outwardly away the main body 18 are heating termatrix against the blank, the 1 in the air from each other to remove the heating terminals from engagement with the blank. The foot lever 11 is then actuated and the matrix 10 strikes a rapid succession of blows upon the heated outer face 4 of the blank.

Since the blank has the outwardly tapering end portion 6, the temperature of the outer face 4 of the blank will be maintained for a long time so that the forming operation can completely take place while the outer face of the blank is hot.

With the above method, the highly repetitive succession of light blows of the matrix caused by the air hammer imparts a surface impact to the blank, thereby insuring surface flow or forging of the blank to the exact sharpness of detail of the matrix being used. This exact sharpness of detail cannot be secured by a slow steady pressureof a matrix unless the blank is heated and is completely confined in a supporting guide. Furthermore, this latter method is not as practical and as good results cannot be secured as by my above described method.

What I claim as my invention is: 1. The method of forming a stamp, comprising the clamping of a blank at a substantial distance from one of its faces, the heating of the blank adjacent to its clam ing means and the sub'ecti of said face 0 the blank to a succession o blows by a matrix, while said face is heated.

2. The method of forming a stamp, com-- prising the subjecting of a 'blank to a rapid repetitive succession" of light blows by a matrix.

3. The method of forming a stamp consisting of clamping a blank at one end thereof, heating the free end of said blank and subjectin the heated free end of said blank to a rapi succession of light blows from the matrix of an air hammer.

In testimon GEO 

